Many industrial gases contain H2S and other sulfur compounds. Examples include, but are not limited to, fuel gases, Claus plant tail gases, and hydrocarbon feeds for refining and other processes. The removal of sulfur compounds from gas streams is an important part of industrial processes including those used in petroleum refining operations. Sulfur is both an environmental hazard when it is a contaminant in fuel for combustion and a poison for several catalytic materials when used in electrochemical systems such as fuel cells. Environmental regulations have been implemented to limit sulfur compound emissions and require higher levels of sulfur capture from the Claus process tail gas. Sulfur removal technologies with a smaller footprint are also highly desirable for space-limited facilities.
Currently, there are number of commercially available technologies in place for sulfur compound removal from the tail gas of the Claus process. However, the large footprint is a constraint for implementation of such technologies in space limited facilities such as offshore oil and gas processing plants or for retrofitting in refineries. High energy consumption and high maintenance costs associated with these technologies is another challenge that has not been sufficiently addressed. Commercially available sulfur removal technologies such as Beavon-MDEA, SCOT, and ARCO, all rely on energy intensive amine scrubbing and regeneration processes. In addition, the water removal steps in these processes impose high capital and operating costs.
Clearly, better sorbent compositions and methods for removing sulfur compounds are desirable.